198 research outputs found
Reproducibility of Intravascular Ultrasound iMAP for Radiofrequency Data Analysis: Implications for Design of Longitudinal Studies
Two decades after coronary radiation therapy: A single center longitudinal clinical study
Objectives: The aim of this study was to evaluate the very long-term clinical outcome after radioactive stent (RS) implantation and intracoronary β radiation brachytherapy (IRBT). Background: Radioactive stents (RS) and intracoronary β radiation brachytherapy (IRBT) were introduced to prevent restenosis after percutaneous coronary intervention (PCI). Both techniques were associated with a higher incidence of major adverse cardiac events (MACE) in the short and intermediate-term follow up as compared to conventional PCI. Methods: One hundred and thirty-three patients received radioactive stents (32P) and 301 patients were treated with IRBT adjunctive to PCI. These groups were propensity matched to respectively 266 and 602 control patients who were treated with routine PCI during the same inclusion period. Endpoints were all-cause mortality and MACE, defined as all-cause death, any myocardial infarction or any revascularization. Results: Median follow-up duration was 17 years. All-cause mortality rates were similar in all groups. Adjusted hazard ratios for MACE and mortality in the RS cohort were 1.55 (95% CI 1.20–2.00) and 0.92 (95% CI 0.63–1.34), respectively. Adjusted hazard ratios for MACE and all-cause mortality in the IRBT cohort were 1.41 (95% CI 1.18–1.67) and 0.95 (95% CI 0.74–1.21), respectively. The difference in MACE rates was predominantly driven by coronary revascularizations in both groups, with a higher MI rate in the IRBT group as well. Conclusions: Coronary radiation therapy was associated with early increased MACE rates, but the difference in MACE rates decreased beyond 2 years, resulting in a comparable long-term clinical outcome. Importantly, no excess in mortality was observed
AUTOMATED QUANTITATIVE ASSESSMENT OF CORONARY CALCIFICATION USING INTRAVASCULAR ULTRASOUND
Coronary calcification represents a challenge in the treatment of coronary artery disease by stent placement. It negatively affects stent expansion and has been related to future adverse cardiac events. Intravascular
ultrasound (IVUS) is known for its high sensitivity in detecting coronary calcification. At present, automated quantification of calcium as detected by IVUS is not available. For this reason, we developed and validated an optimized
framework for accurate automated detection and quantification of calcified plaque in coronary atherosclerosis as
seen by IVUS. Calcified lesions were detected by training a supported vector classifier per IVUS A-line on manually
annotated IVUS images, followed by post-processing using regional information. We applied our framework to 35
IVUS pullbacks from each of the three commonly used IVUS systems. Cross-validation accuracy for each system
was >0.9, and the testing accuracy was 0.87, 0.89 and 0.89 for the three systems. Using the detection result, we propose an IVUS calcium score, based on the fraction of calcium-positive A-lines in a pullback segment, to quantify
the extent of calcified plaque. The high accuracy of the proposed classifier suggests that it may provide a robust
and accurate tool to assess the presence and amount of coronary calcification and, thus, may play a role in imageguided coronary interventions. (E-mail: [email protected]
Plaque burden is associated with minimal intimal coverage following drug-eluting stent implantation in an adult familial hypercholesterolemia swine model
Abstract Safety and efficacy of coronary drug-eluting stents (DES) are often preclinically tested using healthy or minimally diseased swine. These generally show significant fibrotic neointima at follow-up, while in patients, incomplete healing is often observed. The aim of this study was to investigate neointima responses to DES in swine with significant coronary atherosclerosis. Adult familial hypercholesterolemic swine (n = 6) received a high fat diet to develop atherosclerosis. Serial OCT was performed before, directly after, and 28 days after DES implantation (n = 14 stents). Lumen, stent and plaque area, uncovered struts, neointima thickness and neointima type were analyzed for each frame and averaged per stent. Histology was performed to show differences in coronary atherosclerosis. A range of plaque size and severity was found, from healthy segments to lipid-rich plaques. Accordingly, neointima responses ranged from uncovered struts, to minimal neointima, to fibrotic neointima. Lower plaque burden resulted in a fibrotic neointima at follow-up, reminiscent of minimally diseased swine coronary models. In contrast, higher plaque burden resulted in minimal neointima and more uncovered struts at follow-up, similarly to patients’ responses. The presence of lipid-rich plaques resulted in more uncovered struts, which underscores the importance of advanced disease when performing safety and efficacy testing of DES
Comparison of plaque prolapse in consecutive patients treated with Xience V and Taxus Liberte stents
The purpose of this article is to investigate the prevalence of plaque prolapse (PP) after Xience V and Taxus Liberte stent implantation. During the study period 2006-2007, 200 consecutive patients underwent coronary revascularization for de novo lesions and received an intravascular ultrasound (IVUS) post-stenting evaluation, (n = 124 patients with Taxus Liberte and n = 76 with Xience V) (227 stent segments). Cross-sectional and longitudinal 3D IVUS images were analyzed in a blind fashion, evaluating the prevalence of PP and calculating its depth and angle. The angulation degree of the coronary artery at the lesion site pre-stent implantation was also evaluated by angiography. The prevalence of PP was 23.9% in Xience V versus 38.1% in Taxus Liberte (P = 0.025). The depth and angle of PP were greater in Taxus Liberte stent than Xience V stent (0.4 ± 0.1 mm versus 0.5 ± 0.2 mm, P = 0.004; and 32.0 ± 8.9° versus 44.6 ± 27.6°, P = 0.044, respectively). The angulation degree of the coronary artery at the lesion site was higher in presence of plaque prolapse than in its absence (48.2 ± 29.3° vs. 38.2 ± 28.1°, P = 0.013). By multivariate analysis, stent type was independently associated with incidence of plaque prolapse. Xience V stent has less plaque prolapse than Taxus Liberte stent. Stent design may play a role in the prevalence of plaque prolapse
In-vitro and in-vivo imaging of coronary artery stents with Heartbeat OCT
To quantify the impact of cardiac motion on stent length measurements with Optical Coherence Tomography (OCT) and to demonstrate in vivo OCT imaging of implanted stents, without motion artefacts. The study consists of: clinical data evaluation, simulations and in vivo tests. A comparison between OCT-measured and nominal stent lengths in 101 clinically acquired pullbacks was carried out, followed by a simulation of the effect of cardiac motion on stent length measurements, experimentally and computationally. Both a commercial system and a custom OCT, capable of completing a pullback between two consecutive ventricular contractions, were employed. A 13 mm long stent was implanted in the left anterior descending branch of two atherosclerotic swine and imaged with both OCT systems. The analysis of the clinical OCT images yielded an average difference of 1.1 ± 1.6 mm, with a maximum difference of 7.8 mm and the simulations replicated the statistics observed in clinical data. Imaging with the custom OCT, yielded an RMS error of 0.14 mm at 60 BPM with the start of the acquisition synchronized to the cardiac cycle. In vivo imaging with conventional OCT yielded a deviation of 1.2 mm, relative to the length measured on ex-vivo micro-CT, while the length measured in the pullback acquired by the custom OCT differed by 0.20 mm. We demonstrated motion artefact-free OCT-imaging of implanted stents, using ECG triggering and a rapid pullback
Culprit lesion plaque characterization and thrombus grading by high-definition intravascular ultrasound in patients with ST-segment elevation myocardial infarction
Percutaneous Coronary Interventions Using a Ridaforolimus-Eluting Stent in Patients at High Bleeding Risk.
BACKGROUND: Patients treated with percutaneous coronary intervention are often considered to be at a high bleeding risk (HBR). Drug-eluting stents have been shown to be superior to bare-metal stents in patients with HBR, even when patients were given abbreviated periods of dual antiplatelet therapy (DAPT). Short DAPT has not been evaluated with the EluNIR ridaforolimus-eluting stent. The aim of this study was to evaluate the safety and efficacy of a shortened period of DAPT following implantation of the ridaforolimus-eluting stent in patients with HBR. METHODS AND RESULTS: This was a prospective, multicenter, binational, single-arm, open-label trial. Patients were defined as HBR according to the LEADERS-FREE (Prospective Randomized Comparison of the BioFreedom Biolimus A9 Drug-Coated Stent versus the Gazelle Bare-Metal Stent in Patients at High Bleeding Risk) trial criteria. After percutaneous coronary intervention, DAPT was given for 1 month to patients presenting with stable angina. In patients presenting with an acute coronary syndrome, DAPT was given for 1 to 3 months, at the investigator's discretion. The primary end point was a composite of cardiac death, myocardial infarction, or stent thrombosis up to 1 year (Academic Research Consortium definite and probable). Three hundred fifteen patients undergoing percutaneous coronary intervention were enrolled, and 56.4% presented with acute coronary syndrome; 33.7% were receiving oral anticoagulation. At 1 year, the primary end point occurred in 15 patients (4.9%), meeting the prespecified performance goal of 14.1% (P<0.0001). Stent thrombosis (Academic Research Consortium definite and probable) occurred in 2 patients (0.6%). Bleeding Academic Research Consortium type 3 and 5 bleeding occurred in 6 patients (1.9%). CONCLUSIONS: We observed favorable results in patients with HBR who underwent percutaneous coronary intervention with a ridaforolimus-eluting stent and received shortened DAPT, including a low rate of ischemic events and low rate of stent thrombosis. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03877848
Optical Coherence Tomography: Potential Clinical Applications
Optical coherence tomography (OCT) is a novel intravascular imaging modality using near-infrared light. By OCT it is possible to obtain high-resolution cross-sectional images of the vascular wall structure and assess the acute and long-term effects of percutaneous coronary intervention. For the time being OCT has been mainly used in research providing new insights into the pathophysiology of the atheromatic plaque and of the vascular res
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